LOUISVILLE, Ky. (WDRB) – A team of Mercy Academy students mapped a new underwater passage in Mammoth Cave National Park. With a new school year, the all-girl team plans to add to last year’s historic discovery as they continue to explore the underwater cave systems.

Two years ago, Steve Hammer started the club with a team of students interested in S.T.E.M. (Science, Technology, Engineering, and Math) activities. Hammer is the engineering and design teacher at Mercy. The first group started tinkering with drones at first. Then, hoping to try something new, Hammer suggested they look into building a remote operated vehicle, or ROV.

The team built and programmed an underwater ROV. They named it Oscar, with each letter standing for a girl’s name on the team. Hammer said it took about ten hours to build. Oscar is outfitted with cameras, lights, lasers and sensors to take measurements underwater. The ROV is then connected to a computer by a tether. All the data is fed from Oscar through that tether to the computer, and the team pilots the ROV from the shore.

Hammer reached out to scientists at Mammoth Cave National Park to see if the girls could try using the ROV in some of the underwater passages. The National Park Service was thrilled at the chance to explore some areas too small for divers.

Eric Wong is the ecology teacher at Mercy Academy and also an adviser for the team. He helped design the research protocol and plan what the group would do once they got down in the cave.

The team made eight trips last year to the park with Oscar. They had to hike two miles deeper into the cave than the normal tourist attractions.

“We went into it knowing that we’d be in places where no one has ever been before,” Olivia Waldridge said. “And that’s kind of amazing.”

Waldridge, now a senior at Mercy, joined the group last year. She said at first, the girls were just poking around to see what was down there.

Shelby Sherrill, also a student on the team, said everyone would get excited whenever they would see a crawfish or some sort of man-made structure on the screen. Sherrill graduated last year, and she said she’s sad she’ll miss out on any future expeditions.

Mammoth Cave is considered the longest cave system in the world. It’s still unclear how many of the underwater passages connect.

“The further we got in there, the more we realized the further we could go,” Waldridge said.

The team wondered if they could do more than document animal or structure sightings. So they started mapping the waterways.

“We’re mapping where the water is coming from and how we can get from this point in the water system to over here,” Sherrill said.

With curiosity at an all-time high, they started piloting Oscar through unknown water and ended up making history. The ROV found its way through a passage from River Styx to the Dead Sea.

“We found out we had actually gone into another system,” Waldridge said excitedly. “And we didn’t even know, no one knew, it was connected. And so that moment was just really amazing. Everyone was freaking out like, 'I see the light! I see light!'”

A scientist from the national park was standing away from the group on another side of the cave. She saw the light from the ROV flicker in the water. It was that moment everyone realized the ROV found an unknown connection between two bodies of water.

“It’s hard to put into words what you feel when you’ve done something no one ever has done,” Wong said.

The teachers are proud of the students’ accomplishment. Even when the ROV (and backup ROV) got stuck and had to be retrieved by divers, Wong and Hammer said the girls showed impressive problem solving skills.

The teachers said the teenagers are working on research at a high caliber not normally found at the high school level. And both said they are thrilled the students are being treated as professionals.

The research will continue in the 2017-18 school year. The group will continue exploring Mammoth Cave to add more detail to the map. Hammer said they are considering adding technology to the ROV that would allow it to create a 3D image of the underwater cave systems it explores. For the students and the National Park Services, the possibilities are endless.

“We could potentially find some air gaps along the way as well,” Hammer said. “If we find air gaps along there, those would be new open areas of the cave that have not been discovered yet.”

Both Waldridge and Sherrill encourage all students with any interest in S.T.E.M. learning to get creative and think outside the box. They said mapping Mammoth Cave is an experience they will never forget.

“We’re seeing all these things for the very first time,” Waldridge said. “Stuff that divers haven’t even been able to see. Being able to say that as young as we are, that we’re doing legitimate research, is just amazing. I love it.”